Single-ply packing ring with inclosed expander



E March 17, 1931. T A BOWERS 1,796,883

SINGLE-FLY PACKLNG RING WITH INCLOSED EXPANDE'R' Filed July 11. 1930Mail , in g ring must fit snugly in the cylinder bore Patented Mar. 17',193 1 UNI-TED STATES.

PA N oFFrcE THQMASA. BO-WERS, OFZBOSTOiNi,MASSACHUSETTS, ASSIGNOR T0PRESSED rIs'roN RING coMrAnY, A CORPORATION or MASSACHUSETTS.

Application filed July; 11, 19.301; Serial in; 467,253.

My present invention relates'gto packing,

rings and more particularly to packing rings for use in combination withreciprocatingpistons which are used in steam eng1ncS,.1n--

ternal combustion engines, air compressors,

pumps and the like.- I

In the engineeringfielditisa well known and universally recognized factthat a packof the engine at all points around the periphery of the ringin orderito prevent lea-k,-

ao'e of compression and oila-nd that an ideal piston ring should havesome of .the clnn'aclcristics of rubber but at the same 7 time stand upunder heat, friction and other elements to which it is exposed'which, ofcourse, rubber would not do. I

Hcrctofore, practically all packingsrings for pistons have been madefrom cast metal such as cast iron either inoneform or another in whichthe ringis split at one point on its side by cutting a section of thering awa A. ring of this type normally presents a periphery which is atrue circle except where the slot or cut-away portion occurs. Thisnormal periphery is larger in diameter than the bore of the cylinder inwhich it is to be placed and is reduced in diameter to fit such bore bypressing the ring together at the cut-away portion. lVhcn a ring of thischaracter is so pressed together for the purpose of reducing itsdiameter for insertion in a cylinder bore in combination with a piston,the natural formation or shape of the ring is slightly oval in shapeabout its periphery and in order to force it into the bore of thecylinder the back sides of the ring with respect to the slotted sidemust be deformed or bent outward against the walls of the cylinder bore.This against the natural reaction of the ring; The result of thisdeformation is to create an unequal lateral thrust against the wall ofthe cylinder varying at different points about the wall and reaching a.maximum point adjacent that portion of the ring near the slot. Thiseffect is an inherent feature with all cast metal rings of this typewhich results in Wearing the ring thinner at one point than another andwearing the 'cyl'hiderbore out .of"rou'nd also, to the end that,eventi-rally the sides of the ring remote tro'm the slotted side tend torecede from the wall ofthe cylinder and allow compression top-blow bythe piston and oil to pass in an opposite direction. There are alsoother forces in operation i-na reciprccating engine tending to increasethe oval shape of the cylinder bore, such as piston slap and pistonside-thrust caused by the revolutions about the crank shaft andexcessive clearance between the cylinder wall and piston which may be tosome extent traceable to Many attempts have been. made in the past toconstruct a metal packing ring for pistons and the like which willstand-up me chanically and give uniform flexibility on the cylinderwall, such as relatively thin cast metal rings with separate expanderunits located behind the ring for the purpose of holding the deformedshape against the cylinder wall in a more even degree of side thrust,and while such rings do accomplish the result of forming up to the outof round cylinder bore, yet it does so at the expense of the cylinderWall because of increased friction caused by the extremely high lateralside thrust on the cylinder walls. Most rings of this class, as well asmodified types, are open ended rings-that is, the ends of the slots donot fully close as clearance must be left to allow for expansion underheat.

My present invention, however, is a closed end ring such that the twoends are in contact with each other, the expansion of the ring beingtaken up by the multiplicity of laminations comprlsing the body of thering itself.

In my ring there may be as many as several hundred or more laminationssubstantially arranged in a vertical plane with respect to the cylinderwall, the laminations coacting' against each other in a resilient andcompressible manner. My complete ring is made with a diameter normallyoversizcd with respect to the cylinder bore and when inserted in thebore the piston with rings attached may be pulled down through atapering cone, the small end of which is apworn. rings.

proximately the size of the cylinder here as it enters the cylinderblock. This i. S ction in diameter creates an outward thrust against thecylinder wall uniformally the same at every fraction of a degree aboutthe circumference of the ring. If the bore of the cylinder is slightlyout of round as is the case Where new rings are necessary, the extremeflexibility of my ring allows it to conform to the contour of thecylinder bore without requiring any appreciable amount or thrust as thatpoint over any other'point about the circumference of the ring. If myring is made of the same material or of material having the same degreeof hardness as in the metal type previously discussed, it is readily.apparent thatmy ring will greatly outwear the prior rin without allowingany gases to blow by. hereiore, I can use a metal of a softer characterthan the prior rings, such as bronze, and attain the same length of lifeas would be present in the prior cast metal ring, but, in so glloing, Ihave reduced the wear on the cy inder walls thereby prolonging the lifeand efiiciency of the motor.

The amount of compressibility present in my ring depends upon the gaugeand kind of metal used-that is, the smaller the gauge the greater thenumber of laminations, and

the greater the temper of the material used the greater theexpansibility. As the periphery of the ring wears the spaces between thelaminations slightly expand although such expansion would not beperceptible at any one point with the naked eye and when the ring hasworn sufficiently on its periphery for the spaces between thelaminations to fully expand to their normal limits the ring will be duefor replacement, and such replacement may be accomplished many timeswithout reboring the, cylinder walls while the length of life of any onering may be approximately as long as in acast iron ring, assuming thatthe proper material is used, this being made ossible by the much lighterside thrust use in my ring over'the cast metal types.

While my ring is ideally suited for replacement purposes to correct theoutofl round condition of the cylinder bore, yet, it is also ideallysuited for new installation work because a ring of this character willgreatly prolong the length of life of the cylinder bore-which means moreengine efiiciently in every phase of the motor.

The type of packing ring comprising my present invention andto whichthis application is restricted is composed of a plurality oflamin'ations constructed from a single ribbon of metal. In the preferredform i1- lustrated in the drawings, an internal expander. and supportingwire, or several wires, may be inserted in the body of the metalcomprising the ring laminations, the

masses wire being made of tempered steel adapted to withstand arelatively high degree of heat without becoming annealed.

The principal object of this invention, therefore, is an improvedpacking ring for pistons and the like.

.Another object is a piston packing ring which is compressiblethroughout its lineal dimension. n

Another object is a piston packing ring which is compressible andflexible transversally across the diameter of the ring.

Still another object is a piston packing rin which is closed atits endswhen in use an therefore presents a continuous and substacptiallyunbroken seal around the piston an Other objects and novel featurescomprising the, construction and operation of my invention will appearas the description or the sameprogresses.

, In the drawings illustrating my present invention- Fig. l is aperspective view of one of the preliminary steps in the process offorming the ring material;

Fig. 2 is another step in which the corrugations of the-material havebeen pressed together;

Fig. 3 shows a section of the material in corporating therein a wireexpander and supporting element, the material so being arranged that itslaminated edges arc. adapted to bear directly on the inner wall of thecylinder;

Fig. e-shows a material similar to Fig. 3 excepting the lower crimpededges which have not been swaged oil flat as on the top;

Fig. 5 is the same material shown in previ ous figures but adapted topresent the flattened loops of the corrugations to the wall of thecylinder;

Fig. fi indicates a ring found from the material shown in either Fig. 3,l or 5 previous to insertion in the cylinder of a motor; 1

Fig. 7 is similar to Fig. 6 but showing the ring compressed in thecylinder; Fig. 8 is a fragmentary View of a portion of a ring adjacentits opened and corresponding to the use of the material shown in Figs. 3and 4that is,.the cylinder wall contact side of the ring material beingthe edges of the corrugated and compressed metal rihbon'g- Fig. 9 showsa fragmentary cross section through a,portion of a cylinder wall andpiston illustrating the position of the material shown in Figs. 3, 4 and8 when assemhled for duty;

Fig. 10 shows a fragmentary View of a portion of a ring adjacent itsopened end corresponding to the use of the, material shown in Fig. 5thatis, the cylinder wall masses :3

contact side of the ring material being the flattened loops of thecorrugations;

Fig. 11 is a view similar to Fig. 9 but showing the material illustratedin Figs. and 10 in place in a cylinder assembled for duty, and

Fig. 12 illustrates one method of'inserting the piston provided with theabove de scribed rings in the bore of a motor.

Referring to the drawings, 10 indicates a corrugated ribbon of metalhaving an alternate series of loops 11. The loops 11 are pressedtogether as shown in Fig. 2 such that a substantially solid material isobtained consisting of a reat multiplicity of lamina tions. One or 0thof the looped sides of this material may be flattened by swaging asshown in Figs. 3 and f1 and indicated at 12. The top side of thematerial is always swaged and finished to present a perfectly smoothsurface and contact in the groove 19 of the piston 20 for the purpose ofretaining compression in the cylinder head of the motor. Under certainconditions it may be desirable to admit oil to the back of the ring inthe ring groove 19 for the purpose of providing a cushion for the piston20 when the piston tends to stop and also for lubrication of the ring.The scalloped surface 41 of the ring material allows oil to be forced inbehind the ring to fill the groove 19 on the downward stroke of themotor such that this groove 19 is filled with oil when the piston 20 isat the upper part of the stroke and any slap of the piston will bereduced because then is a pressure of oil being forced into this groove19 at the same time that the slap is in progress. The corrugated edgesof the under side of the ring material forming the scallops 41 alsoprovides means for oiling the walls of the cylinder bore.

In either type of ring as shown in Figs. 3 and 4 grooves are milled inthe back side of the ring for the purpose of inserting therein a springsteel wire 51 or a plurality of wires as the case may warrant. The wire51 is adapted to be fastened loosely in the grooves 50 by swaging overthe outer edges of the groove but at the same time allowing thelaminations 15 of the ring to move on the wire freely. The wire 51performs several functions; it maintains the ring against the cylinderwall, provides, a sup porting element for the ring material and makesossible an easily assembled joint at the en s of the ring.

When constructing a packing ring of this type from a single corrugatedribbon of thin enough material to have the necessary compressibility,difiiculty is encountered in handling the ring before it is inserted ina motor because it is more or less fragile and easily ruptured or bentthereby opening up certain of the laminations such that they cannot bereshaped again properly and although it is very desirable to have a ringmaterial which is very thin in its laminations and which consequentlymay be greatly compressed, yet it is necessary to have some ,means toprevent the material from collapsing inwardly when great force isexerted longitudinally of the ring material.

The enclosed expander wires 51 prevents such collapsing and at the sametime provides a strengthening means to support the ring material whenthe .ring is being handled prior to insertion in a motor.

Fig. 6 shows a piston 20 with a ring 21 around the piston. It will benoted that the wire 51 is shown out of the material which may beconstructed as in Fig. 8 or 10. The ring 21 is now pressed together, theend of the wire 51 entering the opening 49 (see Figs. 8 and 10) of thering material. The opposite ends of the wire 51 stop at a point short ofthe end of the groove 50 such that the extending end 51 may make anentry into the same groove or opening 50, better shown in Figs. 8 and10. The piston :20 with ring 21 is now pulled down through a taperedcone 16 located above the cylinder block 60, the lower opening of theinner cone surface 17 being slightly larger than the bore 18 of thecylinder block 60. The laminations 16 of the ring now are compressedtightly together with the result that the normal diameter is reduced tothe size of the bore 18 and due to the fact that the laminations have acertain amount of surface expansibility between them there is aconsiderable degree of side thrust set up by the ring on the wall 18 ofthe cylinder block 60.

The ring material may be formed from a spring material if desired andthe laminations may not be compressed together to such an extent thatthey present a solid block, but yet, to the eye, they may present onesolid surface. A small clearance between the laminations 15 of ahundredth part of a thousandth of an inch when multiplied hundreds oftimes, produces a compressibility and expansibility of a considerablefraction of an inch. 1

Figs. 9 and 11 correspond tothe ring material illustrated in Figs. 8 and10 respectively, showing the position and arrangement of the materialwhen in place in the ring grooves of a piston and contacting with thewall 18 of a cylinder block 60.

Having thus described my invention, what I claim as new is 1. In a sheetmetal packing ring for pistons and the like, a ring composed of onecontinuous ribbon of sheet.metal reversally folded upon itself to forma. complete circle, the ends of said material adapted to contacttogether, said material, supported and guided on internally disposedwires, said wires being loosely contained within, said ring material forthe purpose' of allowing the said material to expand and contractthereon,means for locking the ends of said ring material to prevent saidmaterial from getting out ofalignment at said ends.

A flexible packing ring for pistons and the like comprising a singlemetal ribbon bent upon itself to form ,a multiplicity of substantiallycompact folds, the said folds presenting their edges in a parallel planeto the. cylindrical sides of said piston, the tops of said folds swagedoff in a fiat plane for the purpose of making a tight lit along theupper side of the packing ring groove of said piston, the bottoms ofsaid folds left in their natural rounded form and contact ingattheirextreme lowermost points with the lower sides of said packing ringgroove on saidvpiston for the purpose of alio 'ing oil to pass betweenthe said rounded ends of said folds to the back of said ring in saidpiston grooves, a supporting and expander 'wire imbedded longitudinallyin said packingring adapted to lock the ends of said ring togethe andallow longitudinal expansion of said ring on said wire and at the sametime provide lateral side thrust on said ring 13.

3. A longitudinally and transversallv flexible packing ring for pistonsand the like comprising a nmltiplicity of transverse folds reversallybent upon each other, the periphery of said ring comprising the bentendsof said folds being swaged oil' into a flat vertical plane adapted topresent a wearing surface when placed in the cylinder bore of areciprocating engine, a circular wire expander adapted to be looselyimbeddcd in said ring for the purpose of producing radial thrust in saidring and a supporting element for said folds of said ring, said wireadapted to extend beyond one end of said ring and engage in an openingin the material of the opposite end of said ring for the purpose ofmaintaining alignment therebetween.

t. A piston packing ring composed of one continuous corrugated andcompressed ribbon of metal adapted to compressibly butt together at theends of said ring, said compressed corrugations flattened at their bendsand supported together by aninternally disposed wire of spring metal,said wire loosely confined within said corrugations such that the saidcorrugations may expand and contract longitudinally on said wire.

5. A piston packing ring composed of an internal expander wire looselysurrounded by a plurality of laminations, said laminations being formedfrom compressed corrugations folded upon each other in a reverse mannerfrom a single ribbon of metal, the ends of said ring adapted to contactand compress said laminations when used in the bore of a cylinder as apacking rin 6. A piston packing ring comprising in combination acorrugated and compressed ribbon of metal adapted to fit the packingring groove of a piston and produce lateral thrust against the internalbore of a cylinder by lineal contraction of said corrugations, acylindrical supporting member imbedded in said corrugations adapted toincrease said lateral thrust and also provide support for said-corrugations.

7. A piston packing ring material composed of one metal ribbon foldedrevel-sally upon itself to form a ring of rectangular cross section, aninternally disposed wire loosely associated with said material withrespect to its longitudinal dimension and adapted to support and expandthe folds of said material, the bent edges of said. full being flattenedto present a flat surface adjacent the top and bottom side of a pis onpacking ring groove, substantially as shown and described.

R. A piston packing ring material, the periphery of said ring havinglower sealloped edges. each of said scallops comprising one-half of flattop segment, said seallops and said segments comprising one c ntinuousribbon ot' metal supported by an internal wire adapted to close the endsof ,..sa.i l ring in abuttment and produce radiai thrust in said ringmaterial when the said material com-pressed endwise for use in aninternal combustion engine.

9. The combination of a compressihie folded metal ribbon adapted to fitin the paeking ring groove of a piston and a wire expanderlooselyimbcddcd in said folded ribbon and adapted to abutt at its ends andproduce lateral thrust when compressed lengthwise in the bore of acylinder, substantially as shown and described.

In testimony whereof, I have ZLlllXCtl my signature.

THOMAS A. BOVERS.

